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Diffstat (limited to 'tinycc/lib/builtin.c')
| -rw-r--r-- | tinycc/lib/builtin.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/tinycc/lib/builtin.c b/tinycc/lib/builtin.c new file mode 100644 index 0000000..e40a003 --- /dev/null +++ b/tinycc/lib/builtin.c @@ -0,0 +1,164 @@ +/* uses alias to allow building with gcc/clang */ +#ifdef __TINYC__ +#define BUILTIN(x) __builtin_##x +#define BUILTINN(x) "__builtin_" # x +#else +#define BUILTIN(x) __tcc_builtin_##x +#define BUILTINN(x) "__tcc_builtin_" # x +#endif + +/* ---------------------------------------------- */ +/* This file implements: + * __builtin_ffs + * __builtin_clz + * __builtin_ctz + * __builtin_clrsb + * __builtin_popcount + * __builtin_parity + * for int, long and long long + */ + +static const unsigned char table_1_32[] = { + 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, + 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9 +}; +static const unsigned char table_2_32[32] = { + 31, 22, 30, 21, 18, 10, 29, 2, 20, 17, 15, 13, 9, 6, 28, 1, + 23, 19, 11, 3, 16, 14, 7, 24, 12, 4, 8, 25, 5, 26, 27, 0 +}; +static const unsigned char table_1_64[] = { + 0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28, + 62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11, + 63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10, + 51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12 +}; +static const unsigned char table_2_64[] = { + 63, 16, 62, 7, 15, 36, 61, 3, 6, 14, 22, 26, 35, 47, 60, 2, + 9, 5, 28, 11, 13, 21, 42, 19, 25, 31, 34, 40, 46, 52, 59, 1, + 17, 8, 37, 4, 23, 27, 48, 10, 29, 12, 43, 20, 32, 41, 53, 18, + 38, 24, 49, 30, 44, 33, 54, 39, 50, 45, 55, 51, 56, 57, 58, 0 +}; + +#define FFSI(x) \ + return table_1_32[((x & -x) * 0x077cb531u) >> 27] + (x != 0); +#define FFSL(x) \ + return table_1_64[((x & -x) * 0x022fdd63cc95386dull) >> 58] + (x != 0); +#define CTZI(x) \ + return table_1_32[((x & -x) * 0x077cb531u) >> 27]; +#define CTZL(x) \ + return table_1_64[((x & -x) * 0x022fdd63cc95386dull) >> 58]; +#define CLZI(x) \ + x |= x >> 1; \ + x |= x >> 2; \ + x |= x >> 4; \ + x |= x >> 8; \ + x |= x >> 16; \ + return table_2_32[(x * 0x07c4acddu) >> 27]; +#define CLZL(x) \ + x |= x >> 1; \ + x |= x >> 2; \ + x |= x >> 4; \ + x |= x >> 8; \ + x |= x >> 16; \ + x |= x >> 32; \ + return table_2_64[x * 0x03f79d71b4cb0a89ull >> 58]; +#define POPCOUNTI(x, m) \ + x = x - ((x >> 1) & 0x55555555); \ + x = (x & 0x33333333) + ((x >> 2) & 0x33333333); \ + x = (x + (x >> 4)) & 0xf0f0f0f; \ + return ((x * 0x01010101) >> 24) & m; +#define POPCOUNTL(x, m) \ + x = x - ((x >> 1) & 0x5555555555555555ull); \ + x = (x & 0x3333333333333333ull) + ((x >> 2) & 0x3333333333333333ull); \ + x = (x + (x >> 4)) & 0xf0f0f0f0f0f0f0full; \ + return ((x * 0x0101010101010101ull) >> 56) & m; + +/* Returns one plus the index of the least significant 1-bit of x, + or if x is zero, returns zero. */ +int BUILTIN(ffs) (int x) { FFSI(x) } +int BUILTIN(ffsll) (long long x) { FFSL(x) } +#if __SIZEOF_LONG__ == 4 +int BUILTIN(ffsl) (long x) __attribute__((alias(BUILTINN(ffs)))); +#else +int BUILTIN(ffsl) (long x) __attribute__((alias(BUILTINN(ffsll)))); +#endif + +/* Returns the number of leading 0-bits in x, starting at the most significant + bit position. If x is 0, the result is undefined. */ +int BUILTIN(clz) (unsigned int x) { CLZI(x) } +int BUILTIN(clzll) (unsigned long long x) { CLZL(x) } +#if __SIZEOF_LONG__ == 4 +int BUILTIN(clzl) (unsigned long x) __attribute__((alias(BUILTINN(clz)))); +#else +int BUILTIN(clzl) (unsigned long x) __attribute__((alias(BUILTINN(clzll)))); +#endif + +/* Returns the number of trailing 0-bits in x, starting at the least + significant bit position. If x is 0, the result is undefined. */ +int BUILTIN(ctz) (unsigned int x) { CTZI(x) } +int BUILTIN(ctzll) (unsigned long long x) { CTZL(x) } +#if __SIZEOF_LONG__ == 4 +int BUILTIN(ctzl) (unsigned long x) __attribute__((alias(BUILTINN(ctz)))); +#else +int BUILTIN(ctzl) (unsigned long x) __attribute__((alias(BUILTINN(ctzll)))); +#endif + +/* Returns the number of leading redundant sign bits in x, i.e. the number + of bits following the most significant bit that are identical to it. + There are no special cases for 0 or other values. */ +int BUILTIN(clrsb) (int x) { if (x < 0) x = ~x; x <<= 1; CLZI(x) } +int BUILTIN(clrsbll) (long long x) { if (x < 0) x = ~x; x <<= 1; CLZL(x) } +#if __SIZEOF_LONG__ == 4 +int BUILTIN(clrsbl) (long x) __attribute__((alias(BUILTINN(clrsb)))); +#else +int BUILTIN(clrsbl) (long x) __attribute__((alias(BUILTINN(clrsbll)))); +#endif + +/* Returns the number of 1-bits in x.*/ +int BUILTIN(popcount) (unsigned int x) { POPCOUNTI(x, 0x3f) } +int BUILTIN(popcountll) (unsigned long long x) { POPCOUNTL(x, 0x7f) } +#if __SIZEOF_LONG__ == 4 +int BUILTIN(popcountl) (unsigned long x) __attribute__((alias(BUILTINN(popcount)))); +#else +int BUILTIN(popcountl ) (unsigned long x) __attribute__((alias(BUILTINN(popcountll)))); +#endif + +/* Returns the parity of x, i.e. the number of 1-bits in x modulo 2. */ +int BUILTIN(parity) (unsigned int x) { POPCOUNTI(x, 0x01) } +int BUILTIN(parityll) (unsigned long long x) { POPCOUNTL(x, 0x01) } +#if __SIZEOF_LONG__ == 4 +int BUILTIN(parityl) (unsigned long x) __attribute__((alias(BUILTINN(parity)))); +#else +int BUILTIN(parityl) (unsigned long x) __attribute__((alias(BUILTINN(parityll)))); +#endif + +#ifndef __TINYC__ +#if defined(__GNUC__) && (__GNUC__ >= 6) +/* gcc overrides alias from __builtin_ffs... to ffs.. so use assembly code */ +__asm__(".globl __builtin_ffs"); +__asm__(".set __builtin_ffs,__tcc_builtin_ffs"); +__asm__(".globl __builtin_ffsl"); +__asm__(".set __builtin_ffsl,__tcc_builtin_ffsl"); +__asm__(".globl __builtin_ffsll"); +__asm__(".set __builtin_ffsll,__tcc_builtin_ffsll"); +#else +int __builtin_ffs(int x) __attribute__((alias("__tcc_builtin_ffs"))); +int __builtin_ffsl(long x) __attribute__((alias("__tcc_builtin_ffsl"))); +int __builtin_ffsll(long long x) __attribute__((alias("__tcc_builtin_ffsll"))); +#endif +int __builtin_clz(unsigned int x) __attribute__((alias("__tcc_builtin_clz"))); +int __builtin_clzl(unsigned long x) __attribute__((alias("__tcc_builtin_clzl"))); +int __builtin_clzll(unsigned long long x) __attribute__((alias("__tcc_builtin_clzll"))); +int __builtin_ctz(unsigned int x) __attribute__((alias("__tcc_builtin_ctz"))); +int __builtin_ctzl(unsigned long x) __attribute__((alias("__tcc_builtin_ctzl"))); +int __builtin_ctzll(unsigned long long x) __attribute__((alias("__tcc_builtin_ctzll"))); +int __builtin_clrsb(int x) __attribute__((alias("__tcc_builtin_clrsb"))); +int __builtin_clrsbl(long x) __attribute__((alias("__tcc_builtin_clrsbl"))); +int __builtin_clrsbll(long long x) __attribute__((alias("__tcc_builtin_clrsbll"))); +int __builtin_popcount(unsigned int x) __attribute__((alias("__tcc_builtin_popcount"))); +int __builtin_popcountl(unsigned long x) __attribute__((alias("__tcc_builtin_popcountl"))); +int __builtin_popcountll(unsigned long long x) __attribute__((alias("__tcc_builtin_popcountll"))); +int __builtin_parity(unsigned int x) __attribute__((alias("__tcc_builtin_parity"))); +int __builtin_parityl(unsigned long x) __attribute__((alias("__tcc_builtin_parityl"))); +int __builtin_parityll(unsigned long long x) __attribute__((alias("__tcc_builtin_parityll"))); +#endif |